Back in early August I posted about my misfire eng. code keeps showing up. Couldn't seem to get rid of it. I never felt a misfire with the car.

I took the advice of the forum and:

1'st...... purchased new plugs and got rid of the old NGK's. Definitely made an increase on performance but did not eliminate the Misfire code (always the same code)

2nd.....purchased new coil packs. Again seems as thought it is running great!! but did not eliminate the Misfire code.

3rd.....pulled the wires apart and cleaned, taped and silicone sealed so to prevent any arcing but did not eliminate the Misfire code.

I was about ready to throw the towel in but here's what has happened.

Must preface by stating that I used my code reader as usual to eliminate the misfire code....at least for 5 or so minutes!!!

While starting my morning out I decided to switch on Sport Mode on the Gear shift.

I passed the 5 minute mark w/o any engine failure code showing up....surprise and curious???

I has now been 4 days w/the selector in Sport Mode and NO!!! Engine Code Misfire codes showing up!!!!

I don't think it is coincidence.

DOES ANYONE HAVE ANY IDEAS??????


Thanks

Softball60/Paul

 

Try switching back and see if it reappears

 

Update,

Did not have to put it back in Normal position on the switch. As I was backing out of the driveway in the Sport position on the switch, it started blinking with the Engine Light.!!!!! Same code "Misfire" This thing is running so smooth, it just doesn't make sense......

I am at a loss.....It has to be something in the program.

Please solicit your thoughts

Softball6/Paul

 

Post the actual fault codes. Gives people a better chance of helping you out mate.

 

There are two (2) codes that show up.

first is P0300 and the second is P1313.

Thanks

Softball60/Paul

 

Not sure you have a similar problem, but I had the same codes showing up that ended up being cured by replacing the intake manifold gaskets.

The difference is that I would see the idle dip and occasionally even stall out at a red light or stop sign!

You don't seem to be reporting any of that, however two other garages were not able to find that vacuum leak at the manifold, so apparently it's a tricky problem to spot.

If you end up doing it yourself, make sure your replace the water hose in there, as well as perhaps the oil pressure sensor.

 

Vee,

Thanks for the input. Not sure if I have an intake leak.

On my scanner it seems to be indicating the control module for the trans. Not sure what that has to do with anything.

I have read in other areas that the trans power control module could have an effect if it is shifting not when its supposed to!!!

The car seems to runs great

I may just spring for a used control module on ebay for $22 and guaranteed to work.

Thanks

Softball60/Paul

 

Did you remove your O2 sensor leads sometime in the past? I got the P1313 code after I had new converters installed at a shop and it turns out they had reversed the rear sensor leads. I traced the wires (color coded), switched the leads and cleared up the problem.

 

Rick,

Have not touched/removed the O2 sensors but will check.

I am going to clean the MAF sensor also.

Thanks

Softball60/Paul

 

If throw $22 at a problem. At worst, you have a $22 spare part.

Cleaning MAF is an $8 investment for MAF cleanser.

O2 sensor confusion would require some free time swapping the O2 plugs around. I think they're all located at the rear of the engine.

 

Based on what has been happening I am trying to be very aware of when the check engine light goes on.

Scenario:

All codes have been cleared

I noticed this morning as I was taking the car out that when it was going through the shift pattern (from 1st to 2nd) at about 35mph. a slight hesitation in the shift occurred.

Sure enough......~30 seconds or so later the light went on.

It's not like there was a sudden jerk like a "misfire" more like a hesitation in the shift.

It showed up in the code read.

I'm not sure what all of this means but I am going to list it out and maybe you can understand.

Code- P0303 Random misfire all cylinders

• MIL Status............................................ Off
• Misfire Monitor......................................OK
• Fuel System Monitor..............................OK
• COMP. Component................................OK
• Catalyst Monitor...................................INC
• HTD Monitor........................................N/A
• Evap System Monitor............................INC
• SEC Air System....................................OK
• AC Refrigeration...................................N/A
• Oxy sensor Monitor...............................OK
• Oxy sensor HTR....................................INC
• EGR System.........................................INC

Code -DTCFRZF-1313

Fuel System 1.........................................OL
Fuel System 2.........................................CL
Load Pct............................................... ..36.5%
ETC Degree F..........................................151
SHRTFT1 %.............................................10.2 %
"" 2................................................. 5.5%
LongTFT2 %.............................................10.2 %
RPM............................................... ..........1314 RPM
USS MPH............................................... ...35 mph

This is everything that has showed up on the code reader.

Makes sense as I was at a stop sign, so at 35mph & 1314RPM's is when I felt the slight hesitation.

All comments are appreciated.

Next time I drive I will check again.

Thanks

Softball60/Paul

 

P0303 is telling you that cylinder #3 is misfiring. That would be the third coil from the front of the car. (Coil #1 is the closest to the front, then #2, and so on with #6 being closest to the driver of the car)


That narrows your problem considerably.


I would recommend rerunning your test as you said you would do, and see if the same cylinder is detected. If that's the case, swap two coils (one of the two being the #3 coil) and see if the fault continues at #3, or moves to the new cylinder.


If it moves to the new cylinder, you have a bad coil. If it stays with #3, report back.

 

Vee,

Sorry I made a mistake. The code was actually P0300, Random Cylinder misfire.

Yesterday I check the MAF and and other hoses.

Found several that were very loose. Tightened them up and check w/a drive and........ "no light"!!!!!.

This morning pulled off the MAF sensor and cleaned w/proper MAF Cleaner, retightned the hoses incl. the PCV and thoroughly cleaned the throttle body, etc.,
drove the car and still no engine light.

At least at this point it didn't seems to hesitate while going through the shift pattern. Car is in Sport Mode.

Thanks

Softball60/Paul

If this doesn't solve the situation.

 

would be interesting to see your LONGTFT and SHRTFT since tightning the hoses.

10.2% short fuel trim2 + 10.2% long fuel trim2 giving 20.4% total trim on the number 2 is high.

Strange that your reader is only showing LTFT2 and not LTFT1 as well and that your STFT are out by 5% of each other.

your showing one fuel system in open loop and one in closed loop and that would be strange if you have two "channels". Probably worth working out if you should have both 1 and 2 reporting to the reader and if only one should be then if its "channel" 1 or 2 that you should be watching.

A lean fuel mix could of been throwing a missfire code and with no vaccum leak after tightning the hoses could have fixxed your issue as well as cleaning of the MAF.

Check fuel trims both at idle and at higher RPM to see if your readings have changed now.

And of course this might not be anything but i dont like my fuel trims more than + or - 5% so i would be looking to see why if it was me.

 

Newbound,

Thanks for the reply.

1. New Plugs
2. New Coils
3. Cleaned MAF
4. Tightned up vacuum lines

Still had the same code show up

Yesterday I Installed a used ECM I purchased on Ebay..

So far since yesterday And today have not had any Engine Codes showing "misfire"

It would ususally show up while the engine is still relatively cold. Once warmed up from driving usually NO Misfire CODE.

NO Codes through the entire driving cycle. I noticed that the shifts through the gears seem to be more positive.

Don't know if this solved my problem but will keep my fingers crossed.

Thanks

Softball60/Paul